This invention relates to a trimmer apparatus for use in trimming and edging operations. The invention further relates to an edger apparatus for use in edging operations.
The trimmer apparatus of this invention has particular application in the trimming of vegetation in the form of grass, weeds, shrubs, brush, and the like. The trimmer and the edger apparatus of this invention also have particular application in performing edging operations such as at the edges of lawns, around flower beds, around shrubs, along the edges of pathways and the like.
Applicant is aware of a number of prior patents which disclose various forms of wheeled carriages for supporting trimmers. These patents include U.S. Pat. Nos. 3,221,481--Mattson et al.; 4,845,929--Saki et al.; 3,977,078--Pittenjar; 4,936,886--Quillen; 4,182,100--Litter; 4,891,931--Holland; 4,442,659--Enbusk; 4,981,012--Claiborne; 4,829,755--Nance; and 5,408,816--Cartier. These patents do, for the most part, present a number of disadvantages.
Some of these disadvantages are that the operator has to support a major portion of the weight of the apparatus; that the apparatus is not supported near its center of gravity; that the apparatus is designed to be operated lawn-mower fashion so that lateral maneuverability of the apparatus is limited; that the operator can not position himself near the center of gravity of the apparatus during use; that the apparatus can not readily traverse obstacles during use; that the apparatus is bulky and difficult to handle, and that the apparatus restricts the reach of the clearing head of the apparatus during use.
Of the above patents, U.S. Pat. Nos. 3,221,481--Mattson et al. and 4,936,886--Quillen disclose an apparatus which has a trimmer head which is displaceable between a trimming position and an edging position. These two patents present at least some of the same disadvantages discussed above.
Applicant is also the patentee of U.S. Pat. No. 5,279,102 which issued Jan. 18, 1994.
Applicant's prior patent relates to a clearing apparatus and to a carriage for a clearing apparatus which can reduce or overcome one or more of the disadvantages presented by the prior patents discussed above, and by the prior patents and the publication made of record during prosecution of Applicant's Pat. No. 5,279,102.
Applicant's present invention relates to certain additions, improvements or developments in or relating to some aspects of a trimmer apparatus for use in both trimming and edging operations, and to an edger apparatus for use solely in edging operations.
Applicant incorporates Applicant's prior U.S. Pat. No. 5,279,102 by reference into this application. Applicant also hereby makes of record all prior art of record in Applicant's prior Pat. No. 5,279,102.
In accordance with one aspect of this invention, there is provided a trimmer apparatus comprising a trimmer device for use in trimming and edging operations, a carriage to which the trimmer device is mounted to support the trimmer device during use, and a handle for use in guiding the apparatus during use; the trimmer device comprising an elongated support shaft, a power unit mounted at a trailing end of the shaft, a trimmer head mounted at a leading end of the shaft, and a drive connection for connecting the power unit to the trimmer head; the trimmer head having a trimmer blade to operate in a blade plane; the trimmer device having a swivel connection to allow the trimmer head to be swiveled between a trimming position where the blade plane is generally parallel to a support surface supporting material to be trimmed during use, and an edging position where the blade plane is generally at right angles to such a support surface during use; the carriage comprising a frame, and a single support wheel rotatably mounted on the frame to support the frame during use; the trimmer device being mounted to the carriage such that the trimmer apparatus will be supported proximate its center of gravity on the support wheel during use; the handle being positioned for an operator grasping the handle for guiding the apparatus during use, to be positioned to one side of the support wheel and at least partially in line with part of an axial projection of the support wheel during normal use; and the blade plane in its edging position being substantially parallel to and generally in line with the plane of the support wheel.
The elongated support shaft may be a support shaft of any suitable type or of any conventional type for use in trimmer devices. Thus, for example, the elongated support shaft may be in the form of a housing which houses or supports the drive connection. The housing may, for example, be tubular and of circular, oval, square or rectangular sections. The housing may also be of channel section, or the like.
In a presently preferred embodiment, the elongated support member is a tubular housing of circular section which houses the drive connection.
The drive connection may be a drive connection of any suitable or conventional type to operatively connect the trimmer head and the power unit.
Thus, for example, the drive connection may comprise or include a flexible drive shaft, a semi-flexible drive shaft, a drive train or the like, depending upon the configuration of the support shaft, for connecting a power unit in the form of a motor to the trimmer head.
Where the power unit is a battery and the trimmer head has an electrical motor associated with it to drive the trimmer head, the drive connection comprises electrical leads or other power connections leading from the battery to the electrical motor.
The swivel connection may be provided, for example, in the elongated support shaft, may be provided in the trimmer head, or may be provided at the leading end of the elongated support shaft between that leading end and the trimmer head.
In a presently preferred embodiment of the invention, the swivel connection is provided in the shaft to define a swivel axis about which a leading portion of the shaft can be swiveled relatively to a trailing portion of the shaft for swiveling the trimmer head between its trimming and edging positions.
In a preferred embodiment of the invention, the swivel axis is parallel or substantially parallel to the blade plane, and is parallel or substantially parallel to the plane of the support wheel.
The swivel connection may include a swivel lock of any suitable or conventional type for locking the swivel connection in a desired position.
The swivel lock may be adapted to lock the swivel connection in either the trimming position of the trimmer head, or the edging position of the trimmer head. Alternatively, if desired, the swivel lock may be adapted to lock the swivel connection at any intermediate position between the trimming position and the edging position of the trimmer head.
In one embodiment of the invention, the swivel lock may include a threaded swivel pin which is displaceable along a swivel slot, and a nut to cooperate with the threaded swivel pin to lock the threaded swivel pin in position along the swivel slot.
In alternative embodiments of the invention, for example, the swivel lock may comprise one or more spring loaded or displaceable pins or buttons, may comprise a split clamp, may comprise a G-clamp, or any other suitable or conventional swivel lock.
While the shaft may extend parallel to the plane of the support wheel, the shaft preferably has at least a portion of the shaft which extends at an acute angle to the plane of the support wheel to position the trimmer head to one side of the plane of the support wheel during trimming operations.
In one example of the invention, the portion of the support shaft which extends at an acute angle to the plane of the wheel, extends at an angle of between about 2.degree. and about 20.degree. to the plane of the support wheel.
In a presently preferred embodiment of the invention, that portion of the support shaft extends at an angle of between about 10.degree. and about 15.degree. to the plane of the support wheel.
In an embodiment of the invention, the leading portion of the support shaft is an angled portion which extends at an angle of between about 25.degree. and about 75.degree. to the plane of the support wheel when the trimming head is in its trimming position.
More preferably, the leading angled portion of the support shaft extends at an angle of between about 50.degree. and about 60.degree. to the plane of the support wheel when the trimmer head is in its trimming position.
This particular arrangement provides the advantage that when an operator is operating the apparatus with the trimmer head in its trimming position, the trimmer head will be substantially in line with the direction of movement of the operator when the operator is moving in the forward direction. This facilitates the ease of use of the trimmer apparatus of this invention.
When the trimmer head is then swiveled into its edging position, the operator will be able to continue to use the trimmer apparatus while walking substantially parallel to the direction of movement of the support wheel and thus substantially parallel to the line along which the trimmer head is performing its edging function.
In an embodiment of the invention, the leading portion of the shaft may be angled to extend at an angle in the lateral direction from the trailing portion of the shaft when the trimmer head is in its trimming position.
The angled leading portion preferably has a length and angle in relation to the diameter of the trimmer blade, for the swivel connection to be at substantially the same height when the trimmer head is in its trimming position and when the trimmer head is in its edging position during use.
This embodiment of the invention provide the advantage that the angle of the support shaft and the height and positioning of the handle will remain substantially constant when the trimmer head is swiveled between its trimming and edging positions.
This provides the further advantage that the trimmer apparatus will remain supported substantially about its center of gravity on the support wheel when the trimmer apparatus is in its trimming position, and when the trimming apparatus is in its edging position, without the need to adjust the center of gravity.
In one embodiment of the invention, where the diameter of the trimmer blade is about 9 inches, the angled leading portion of the shaft may extend at an angle of between about 40.degree. and about 50.degree. to the trailing portion of the shaft when the trimmer head is in its trimming position.
The trimmer apparatus of this invention may also include an edger guide to guide the height of the trimmer head when the trimmer head is in its edging position.
While the edger guide is preferably mounted on the trimmer head, it may also be mounted on the leading portion of the shaft which can be swiveled relatively to the trailing portion. The edger guide is mounted so that when the trimmer head is displaced into its edging position, the edger guide will be brought into position where it can guide the height of the trimmer head during edging operations. The edger guide may be in the form of a guide wheel, a skid, or the like.
The edger guide may also include a guide flange to guide the edger guide along an edge of a curb, sidewalk, or the like during use to assist in maintaining a constant or relatively constant distance from the curb or sidewalk to the plane of the blade during use.
The edger guide may be mounted on a support flange which is mounted on the trimmer head, on a guard for the trimmer head, or on the shaft.
The support flange may be adjustable to permit adjustment of the height at which the blade is supported during use in edging operations.
The guide flange may be a wheel flange which is mounted on the guide wheel. Alternatively, the guide flange may be mounted on the guard, or on the support flange, or on the shaft.
The guide flange may be adjustable to permit adjustment of the spacing between the guide flange and the blade plane.
In one preferred embodiment of the invention, the handle may be arranged for an operator holding the handle to be positioned proximate the center of gravity of the apparatus during use. Thus for an operator to operate the apparatus during use, the operator will be positioned or will be standing proximate the support wheel. Thus the operator will be positioned at least partially or substantially in line with part of an axial projection of the support wheel during normal use.
In a preferred embodiment, the handle is positioned so that an operator grasping the handle for guiding the apparatus during use, will be partially in line with, or alternatively substantially in line with, an axial extension of the wheel axis during use.
The handle may be positioned proximate the center of gravity of the apparatus. Preferably, the handle may be positioned to extend forwardly of the center of gravity of the apparatus, in the direction of the trimmer head during use.
In different embodiments of the invention, the handle may form part of the carriage, may form part of the trimmer device, may be mounted on the carriage, or may be mounted on the elongated support shaft of the trimmer device.
In an embodiment of the invention, the handle may comprise a guide handle as described for use in guiding the apparatus, and a control handle for use in controlling the apparatus. The control handle may preferably be provided on the trailing side of the center of gravity of the apparatus, while the guide handle is provided on the leading side of-the center of gravity of the apparatus.
In one embodiment of the invention, the control handle may be mounted on the elongated support shaft between the power unit and the carriage. In an alternative embodiment of the invention, the control handle may be mounted on the trailing side of the power unit. The control handle may also be mounted on the power unit, on the carriage, or on the guide handle.
The control handle may preferably include a throttle control or switch or the like for controlling the power unit.
In one preferred embodiment of the invention, the guide handle and control handle may be positioned so that when an operator grasps the two handles to operate the apparatus, he or she will be positioned proximate the center of gravity of the apparatus. Thus the operator will preferably be positioned to one side of the support wheel and partially in line with an axial projection of the axis of the wheel.
The guide handle and the control handle are preferably displaceable relatively to each other and also relatively to the trimmer device, to allow for adjustment of the height and positioning of the handles for different sized operators and for different types of trimmer devices.
In an embodiment of the invention, the positions of the guide handle and of the control handle relative to the center of gravity of the apparatus, may be adjustable to suit the requirements of the operator. Any standard adjustment means may be provided for adjusting the positions and heights of the guide handle and control handle.
The power unit may comprise a motor of any conventional or suitable type for driving the trimmer head during use.
Thus, for example, the power unit may comprise a gasoline motor, an electrical motor, or the like.
In an alternative example of the invention, the power unit may comprise a battery. In this example of the invention, an electric motor may form part of the power unit, and the trimmer device would then have a drive connection such as a drive shaft for connecting the trimmer head to the electric motor. Alternatively, an electric motor may form part of the trimmer head, in which case the drive connection would comprise electrical leads to conduct electricity from the battery to the electric motor at the clearing head.
The support wheel of the apparatus of this invention, may be a wheel of any suitable type. While the support wheel may be relatively small, the wheel should preferably be relatively large since this will give the greatest height to the axle of the wheel and thus improve the ease of handling of the apparatus. The larger the support wheel, the more readily can the apparatus be steered over or past obstacles such as stones, rocks, and bumps, and the more readily can the apparatus be caused to traverse an uneven terrain.
For rough terrain, the support wheel may, for example, be in the form of a conventional bicycle wheel. In one preferred embodiment of the invention the bicycle wheel may for example be a 20, 24 or 26 inch diameter wheel.
In a presently preferred embodiment the wheel may be a 24 inch diameter wheel of the type used in wheel chairs. In an alternative embodiment, for smoother terrain, the wheel is preferably a 12 inch diameter wheel.
The support wheel may have an inflatable tire. Alternatively, the support wheel may have a solid tire, a foam-filled tire, a semi-pneumatic tire, or the like. For light duty applications, the wheel may be a blow-molded plastic wheel.
The support wheel may be provided with a large number of bicycle type spokes. Alternatively, it may be provided with a relatively low number of broad support spokes, or even a disc which has the axle mounted at its center, and a tire or the like at its periphery. Also, the axle of the wheel can preferably be off-set to one side to allow more clearance on the other side of the wheel.
The trimmer head may be in the form of a trimmer head of any suitable or of any conventional type having a trimmer blade of any suitable type. Thus, for example, the trimmer blade may comprise a blade of the line type for use in cutting lighter vegetation such as grass, weeds, smaller shrubs and the like. Blades of the line-type are also referred to as blades of the string-type.
Alternatively, the trimmer blade may comprise an annular blade having circumferentially spaced teeth, having circumferentially spaced sets of teeth, or having a plurality of spaced trimmer blades, trimmer chains, or the like which may be pivotally mounted for cutting heavier vegetation such as weeds, shrubs, large shrubs, including brush, small trees, stalks, and the like.
In a preferred embodiment of the invention, the blade plane in its edging position is parallel to and is substantially in line with the plane of the support wheel.
When the blade plane is substantially in line with the plane of the support wheel in its edging position, the blade plane may be directly in line with the plane of the support wheel, or may be laterally spaced from the plane of the support wheel by several inches.
In one embodiment of the invention, the blade plane may be laterally spaced from the plane of the support wheel by between about 0 and 8 inches, and preferably by about 2 to 5 inches.
The invention further extends to an edger apparatus comprising an edger device for use in edging operations, a carriage to which the edger device is mounted to support the edger device during use, and a handle for use in guiding the edger apparatus during use; the edger device comprising an elongated support shaft, a power unit mounted at a trailing end of the shaft, an edger head mounted at a leading end of the shaft, and a drive connection for connecting the power unit to the edger head; the edger head having an edger blade to operate in a blade plane; the carriage comprising a frame, and a single support wheel rotatably mounted on the frame to support the frame during use; the edger device being mounted to the carriage such that the edger apparatus will be supported proximate its center of gravity on the support wheel during use; the handle being positioned for an operator grasping the handle for guiding the apparatus during use, to be positioned to one side of the support wheel and at least partially in line with part of an axial projection of the support wheel during normal use; and the blade plane being substantially parallel to and generally in line with the plane of the support wheel.
It will be appreciated that the edger apparatus of this invention has many elements in common with the trimmer apparatus of this invention. The same considerations therefore apply to those elements of the edger apparatus of this invention which are common to those elements of the trimmer apparatus of this invention. Thus, for example, the different examples of the elements described for the trimmer head, can apply equally to the edger head.
Embodiments of this invention can provide the advantage that the trimmer apparatus can be used effectively for trimming operations where the apparatus is supported substantially about its net center of gravity on the support wheel, and can be easily handled by an operator. When required for edging operations, the trimmer head can readily be swiveled into an edging position. In the edging position, the trimming head is substantially parallel to and generally in line with the plane of the support wheel. Thus, an operator can effectively control the edging apparatus so that the edging operation is performed in line with the support wheel. This arrangement makes it easy for the operator to judge the line along which edging operations must be performed, and to displace the apparatus on the support wheel along that line for accurate and easy edging operations.